scholarly journals Multiscale Signal Processing and Shape Analysis for an Inverse Sar Imaging System

2001 ◽  
Author(s):  
Yun He
Keyword(s):  
Signal Processing ◽  
Shape Analysis ◽  
Imaging System ◽  
Sar Imaging ◽  
Inverse Sar

scholarly journals Recent developments in high-resolution-gamma-ray cargo-inspection technology

2018 ◽  
Vol 48 ◽  
pp. 1860109
Author(s):  
David Taylor ◽  
Victor Orphan ◽  
Eric Ackermann ◽  
Rhett Barnes ◽  
Ryan Shyffer ◽  
...  
Keyword(s):  
Signal Processing ◽  
High Resolution ◽  
Homeland Security ◽  
Gamma Ray ◽  
Imaging System ◽  
Digital Signal ◽  
Department Of Homeland Security ◽  
Legacy System ◽  
Cargo Inspection ◽  
Signal Processing Electronics

Under US Department of Homeland Security sponsorship, Spectral Labs Incorporated has developed a prototype high-resolution retrofit for an existing mobile VACIS, named the High-Resolution Imaging System (HiRIS). The legacy 256 NaI detectors in the VACIS detector column were replaced with 576 CsI detectors, more than doubling the pixel count. Using SiPMs to replace conventional PMTs allowed the packing of more detectors in the same VACIS detector enclosure. Legacy analog signal-processing electronics were replaced with advanced digital signal-processing electronics. Replacing gross counting in the legacy system with multichannel analysis of the counts from each detector will allow better control of detector crosstalk. The HiRIS detector modules were installed on a VACIS truck refurbished to as-new condition. Initial testing of the HiRIS prototype demonstrates enhanced spatial resolution by a factor of two as compared to the legacy system, without any degradation in throughput capability (20 containers per hour).

scholarly journals A high-precision hardware-efficient radix-2k FFT processor for SAR imaging system

2016 ◽  
Vol 13 (22) ◽  
pp. 20160903-20160903 ◽  
Author(s):  
Chen Yang ◽  
Yizhuang Xie ◽  
He Chen ◽  
Cuimei Ma
Keyword(s):  
High Precision ◽  
Imaging System ◽  
Fft Processor ◽  
Sar Imaging

scholarly journals ANALYSIS OF SAR MAIN PARAMETERS FOR SAR SENSOR DESIGN ON LSA

2017 ◽  
Vol 11 (2) ◽  
pp. 85
Author(s):  
Muchammad Soleh ◽  
Rahmat Arief
Keyword(s):  
Optical Sensors ◽  
Imaging System ◽  
Flight Test ◽  
Imaging Technology ◽  
Range Resolution ◽  
Fundamental Parameters ◽  
Slant Range ◽  
Sar Imaging ◽  
Simulation Results ◽  
Pseudo Data

LAPAN plans to conduct a flight test of LSA (LAPAN Surveillance Aircraft). LSA STEMME-S15 is capable of carrying sensor payloads up to 160 kg that are mounted on both sides of the wings with altitude between 400-2000 m. LSA can be designed to perform imaging by using optical sensors and SAR (Synthetic Aperture Radar). Compared to imaging using optical sensors, SAR sensor has advantages such as it can operate all day and night, able to penetrate clouds, and able to see objects from side looking, while optical sensors generally see the object perpendicular to the ground. Therefore the use of SAR imaging technology can complement optical imaging technology. To design SAR system imagers on LSA, it is necessary to simulate the primary parameters SAR i.e. altitude and look angle of sensor, speed of LSA, SAR frequency and signals power shot to object to calculate the resolution of azimuth and ground range values that can be obtained. This SAR parameters simulation used MATLAB which have been designed with two approaches; the first approach where the SAR sensor is ideal and in which all the fundamental parameters (such as polarization, frequency, etc.) are used to generate the desired sensitivity and resolution of azimuth and ground range, and the second approach is where SAR sensor is designed in a limited antenna size (constraint case), with the assumption that the dimensions of the antenna and the average available power are fixed. The data used in this simulation is a pseudo-data obtained from LSA technical spesification and SAR sensor. The simulation results with the first approach shows that if LSA is flying at an altitude of 1000 m, with speed of 36.11 m/s, and SAR frequency of 5.3 GHz, then to get resolution of azimuth, slant range and ground range of 1 m, 1.2 m and 3 m, it is necessary to design the length and width of SAR antenna at 2 m and 13.5 cm, with look angle of 23.5 degrees. While the result of second approach simulation is that if LSA is flying on the same altitude and speed, on the same look angle and SAR frequency, with a particular design of antenna length and width of 2 m and 13.5 cm, then azimuth, slant range and ground range resolution of 1 m, 1.87 and 4.79 m will be obtained. Form both simulations, it can be concluded that limited SAR system on LSA, especially on the technical aspects of mounting and space as in the simulation with the second approach, will produce slightly lower slant range and ground range resolution when compared with SAR system in the first simulation. This shows that space limitation on LSA will affect decrease the value of spatial ground range resolution. The simulation results are expected to be inputs on designing SAR imaging system on LSA.

Efficient and Flexible 2-D Data Controller for SAR Imaging System

2018 ◽  
Author(s):  
Tianyun Sun ◽  
Yizhuang Xie ◽  
Bingyi Li ◽  
He Chen ◽  
Xiaoning Liu ◽  
...  
Keyword(s):  
Imaging System ◽  
Sar Imaging ◽  
Data Controller

Wavefront Coded Imaging Systems for MEMS Analysis

2002 ◽  
Author(s):  
Daniel L. Barton ◽  
Jeremy A. Walraven ◽  
Edward R. Dowski ◽  
Rainer Danz ◽  
Andreas Faulstich ◽  
...  
Keyword(s):  
Signal Processing ◽  
Real Time ◽  
High Performance ◽  
Imaging System ◽  
Three Dimensional ◽  
Imaging Systems ◽  
Depth Of Field ◽  
Real Time Imaging ◽  
Large Depth ◽  
Wavefront Coding

Abstract A new imaging technique called Wavefront Coding allows real-time imaging of three-dimensional structures over a very large depth. Wavefront Coding systems combine aspheric optics and signal processing to achieve depth of fields ten or more times greater than that possible with traditional imaging systems. Understanding the relationships between traditional and modern imaging system design through Wavefront Coding is very challenging. In high performance imaging systems nearly all aspects of the system that could reduce image quality are carefully controlled. Modifying the optics and using signal processing can increase the amount of image information that can be recorded by microscopes. For a number of applications this increase in information can allow a single image to be used where a number of images taken at different object planes had been used before. Having very large depth of field and real-time imaging capability means that very deep structures such as surface micromachined MEMS can be clearly imaged with one image, greatly simplifying defect and failure analysis.

Bistatic Noise SAR Experiment with a Non-Cooperative Illuminator

2011 ◽  
Vol 57 (1) ◽  
pp. 85-89
Author(s):  
Łukasz Maślikowski ◽  
Krzysztof Kulpa
Keyword(s):  
Signal Processing ◽  
Synthetic Aperture Radar ◽  
Noise Signal ◽  
Synthetic Aperture ◽  
Sar Image ◽  
Measurement Campaign ◽  
Bistatic Sar ◽  
Sar Imaging ◽  
Commercial Off The Shelf ◽  
Build System

Bistatic Noise SAR Experiment with a Non-Cooperative IlluminatorThe paper describes the results of a conception-stage experiment with a ground-based bistatic noise SAR (Synthetic Aperture Radar) demonstrator. Its aim was to research the ability of a simple Commercial-Off-The-Shelf (COTS) build system to provide a bistatic SAR image using non-cooperative illuminator. The noise signal used in the experiment is similar to a signal used in many transmission systems such as DVB-T that can be employed in passive bistatic radars. The paper presents the system setup, details of the measurement campaign, signal processing and the results of SAR imaging.

The Maltese Cross Processor: Speckle Reduction for Circular Transducers

1988 ◽  
Vol 10 (3) ◽  
pp. 153-170 ◽  
Author(s):  
S.W. Smith ◽  
O.T. von Ramm
Keyword(s):  
Signal Processing ◽  
Dynamic Range ◽  
Imaging System ◽  
Speckle Noise ◽  
Processing Technique ◽  
Speckle Reduction ◽  
Ultrasound Images ◽  
Signal Processing Technique ◽  
Aperture Diameter ◽  
Parallel Signal Processing

A new online signal processing technique is described to reduce speckle noise in ultrasound images. In the imaging system, a focused piston transducer is divided into thirty-two sectors. In the receive mode, parallel signal processing arranges the sectors into eight maltese crosses. The rf signals of the perpendicular arms of each cross are multiplied in a phase sensitive process. The orthogonal receive mode multiplication is designed to reduce side lobes resulting from the sector shapes while maintaining lateral resolution through the use of the full aperture diameter. The signals from the crosses are then combined via postdetection summation. Six of the eight crosses perform successfully. The six maltese crosses show decorrelated signals equivalent to four independent samples of the speckle noise which decreases noise contrast by a factor of two with no measureable loss of spatial resolution. Post summation compression is included to retain the conventional signal dynamic range. Parallel signal processing maintains the normal image line rate. Images of tissue-mimicking phantoms including speckle targets show improved detectability of simulated lesions.

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